Q&A with Dr. Yan Li

Uveitis, a leading cause of blindness worldwide, has long challenged ophthalmologists due to its complex diagnosis and monitoring requirements. At Casey Eye Institute, associate professor of ophthalmology Yan Li, Ph.D., and her research team are pioneering an approach that combines ultrahigh-resolution optical coherence tomography (UHR OCT) with artificial intelligence (AI) to transform how we diagnose and track this sight-threatening condition.
In this interview, Dr. Li discusses her innovative work and its potential impact on patient care.
Q: What is ultrahigh resolution OCT, and how does it differ from standard OCT?
Dr. Li: Optical coherence tomography (OCT) is a non-invasive imaging technique that uses light waves to take high-resolution cross-sectional images of the eye. While typical commercial OCT scanners have an axial resolution of 5-10 microns, ultrahigh-resolution OCT uses broadband light sources to achieve axial resolutions as fine as 2.4 microns in tissue—more than twice as precise as standard systems. This enhanced capability represents a significant advancement over standard OCT, which is already a cornerstone of ophthalmic imaging.
Q: How are you using this technology to address uveitis?
Dr. Li: The presence of cells in aqueous or vitreous humor is a hallmark of ocular inflammation. Traditionally, clinicians rely on slit-lamp examination to view and count white blood cells, but this is subjective, semi-quantitative, and requires extensive training and experience. One particular challenge is that we cannot reliably see and count cells in the mid- or posterior vitreous with a slit lamp examination, making the evaluation of posterior uveitis, an important class of inflammatory eye diseases, less precise.
Using UHR OCT combined with AI, we don’t just count these cells – we can also identify their type. This capability is crucial because the differential diagnosis of uveitis is broad and challenging. By identifying both the location and type of inflammatory cells, our system could help diagnose and classify uveitis more accurately. It could also help monitor treatment response with unprecedented precision.
Q: What makes your research unique in this field?
Dr. Li: Our work is unique in several ways. First, we are developing a prototype UHR OCT system that can capture ultrahigh-resolution images of the anterior chamber, vitreous body and retina with extended imaging depth—something that hasn't been done before. We can also differentiate between types of inflammatory cells in both locations, which is unprecedented in the field.
This work builds on pioneering efforts that began in 2004 where David Huang, M.D., Ph.D.—co-inventor of OCT and recent recipient of the National Medal of Technology and Innovation—and I first explored OCT applications for uveitis while we were at Cole Eye Institute, Cleveland Clinic.
Q: How could this technology impact patient care?
Dr. Li: The implications for patient care are significant. Currently, the most common diagnosis at uveitis centers across the United States is "idiopathic," meaning the underlying cause is unknown. More specific diagnostic information could be potentially lifesaving—for instance, in cases of sarcoidosis with cardiac involvement. Additionally, current diagnostic methods, like sampling intraocular cells from the anterior chamber or vitreous cavity, are invasive and carry risks of sight-threatening infection or ocular injury. Our non-invasive approach using UHR OCT and AI could provide crucial diagnostic information while avoiding these risks.
The precision of our system makes it particularly valuable for clinical trials of new drugs, where objective measurements of treatment response are essential.
Q: Can you describe the development process and your collaborations?
Dr. Li: We received an NIH R21 grant to quantify and classify intraocular inflammation using UHR OCT. I'm collaborating with Siyu Chen, Ph.D., assistant professor of ophthalmology and biomedical engineering, to build the prototype system.
To enroll patients in our clinical study, we work with uveitis specialists Eric Suhler, M.D., M.P.H., director of the Casey Eye Institute Uveitis Clinic and chief of ophthalmology at the Portland Veterans Affairs Medical Center, and Erick Rivera-Grana, M.D., at the Casey Eye Institute uveitis clinic. This is a great example of how we can bring engineering expertise and clinical care together at Casey Eye Institute to develop a system that meets real-world diagnostic needs.
Q: What's next for this technology?
Dr. Li: I'm confident that the advancements in OCT technology, imaging processing software and AI will benefit uveitis management. One of the greatest challenges in caring for patients with uveitis has been the lack of objective markers of disease activity—our technology aims to fill this critical gap in care. When ultrahigh-resolution OCT becomes available to clinicians, it will give us objective biomarkers to aid in differential diagnosis of uveitis and assessment of disease severity. This precision will be especially valuable for clinical trials of new drugs and for monitoring treatment response in individual patients.
Looking Ahead to a New Era
The development of this innovative imaging system represents a significant step forward in ophthalmology. By combining advanced OCT with AI, Dr. Li and her team may soon provide clinicians with objective, reliable tools for diagnosing and monitoring uveitis, potentially improving outcomes for patients worldwide.
Learn more
For more information about this research, interested readers can access Dr. Li's presentation from the 2024 ARVO Imaging and the Eye Conference.